JP6884554B2 - Thermal transfer medium - Google Patents

Description

The present invention relates to a thermal transfer medium.

For example, a transfer layer capable of thermal transfer of symbols such as barcodes and characters (hereinafter, may be abbreviated as "characters") is provided on the surface of a label or the like whose surface is at least made of various plastics. Thermal transfer printing may be performed using a thermal transfer medium.
However, characters and the like that are thermally transferred and printed on the above labels using a conventional heat-sensitive transfer medium do not have sufficient resistance (solvent resistance) to various solvents such as alcohol and gasoline, and the labels and the like come into contact with these solvents. When used for various purposes, there is a problem that it easily melts, bleeds, scuffs, or flows.

Therefore, in Patent Document 1, in a thermal transfer medium in which a transfer layer having a two-layer structure of a protective layer and a colored layer is formed on a base material via a release layer, the protective layer is resistant to alcohol (resistance to alcohol) as a binder resin. It is being studied to improve the alcohol resistance of letters and the like by using a polyester resin having excellent alcohol properties.
However, with the polyester resin alone, so-called residual peeling, in which the transfer layer in the non-transfer region adjacent to the thermal transfer region is peeled from the substrate, is likely to occur during thermal transfer printing.

Therefore, in Patent Document 1, in order to improve the film sharpness of the transfer layer and prevent the occurrence of residual peeling, the protective layer further contains a heat-meltable wax having a low film-forming property in a predetermined ratio.
However, since the heat-meltable wax has lower alcohol resistance than the polyester resin, there is a problem that the effect of improving the alcohol resistance of letters and the like is insufficient by including the polyester resin as the binder resin in the protective layer. is there.

In Patent Document 2, the transfer layer of the heat-sensitive transfer medium has a two-layer structure of a first heat-meltable ink layer containing an epoxy resin and a second heat-meltable ink layer containing a polyester resin, particularly polyethylene terephthalate (PET) and the like. It has been proposed to thermally transfer and print characters having excellent alcohol resistance and scratch resistance on the surface of the polyester.
However, the transfer layer has insufficient heat-sensitive adhesiveness to the surface of polyolefins such as polypropylene (PP) and polyethylene (PE) and the transferability associated therewith, and when thermal transfer printing is performed on the surface of the polyolefin, characters and the like due to transfer defects and the like In addition to being prone to blurring and deterioration of sharpness, there is a problem that the alcohol resistance and scratch resistance of thermal transfer printed characters and the like are not sufficient.

On the other hand, in Patent Document 3, the transfer layer has a two-layer structure of a colored layer and an adhesive layer containing chlorinated polyolefin, and characters having excellent alcohol resistance and scratch resistance are thermally transferred and printed on the surface of the polyolefin in particular. Has been proposed.
However, on the contrary, the transfer layer has insufficient thermal adhesiveness and transferability to the surface of the polyester, and when thermal transfer printing is performed on the surface of the polyester, the characters and the like are liable to be blurred or the sharpness is deteriorated due to transfer failure. There is a problem that the alcohol resistance and scratch resistance of characters printed by thermal transfer printing are not sufficient.

Further, all of the characters and the like thermal transfer printed using the thermal transfer medium provided with the transfer layers described in Patent Documents 1 to 3 are more soluble than alcohol regardless of the type of plastic to be thermal transfer printed. There is also a problem that the resistance to strong gasoline (gasoline resistance) is not sufficient.

Japanese Unexamined Patent Publication No. 9-52451 Japanese Unexamined Patent Publication No. 9-193556 Japanese Unexamined Patent Publication No. 2000-168248 Japanese Unexamined Patent Publication No. 2000-303374 Jitsufuku No. 7-120033

An object of the present invention is to improve the heat-sensitive adhesiveness and transferability of a transfer layer regardless of the type of plastic to be subjected to thermal transfer printing, to prevent transfer defects from occurring during thermal transfer printing, and to withstand thermal transfer printed characters and the like. An object of the present invention is to provide a thermal transfer medium capable of improving solvent resistance and scratch resistance.

Bonding the present invention comprises a rolling Utsushiso provided to be thermally transferred onto the substrate, the transfer layer is provided on the outermost layer of the colored layers and, and transfer layer at the side opposite to the substrate of the colored layer The adhesive layer is a thermal transfer medium containing two layers, a cyclized rubber and a chlorinated polyolefin.
Further, the present invention includes a transfer layer provided on a base material so as to be thermally transferable, and the transfer layer includes two layers, a colored layer and a protective layer provided on the base material side of the colored layer, and the protection is provided. The layer is a thermal transfer medium containing a cyclized rubber and the colored layer containing an epoxy resin.

According to the present invention, regardless of the type of plastic to be subjected to thermal transfer printing, the heat-sensitive adhesiveness and transferability of the transfer layer can be improved, transfer defects can be less likely to occur during thermal transfer printing, and the resistance of characters and the like printed by thermal transfer printing can be improved. It is possible to provide a thermal transfer medium capable of improving solvent resistance and scratch resistance.

FIG. (A) is an enlarged cross-sectional view showing a layer structure of an example of the embodiment of the thermal transfer medium of the present invention , and FIG. (B) is an enlarged cross-sectional view showing a layer structure of another example of the embodiment. is there.

The present invention comprises a rolling Utsushiso provided to be thermally transferred onto the substrate as described above, the transfer layer, a colored layer, the outermost layer of the substrate of the colored layer opposite a and transfer layer The adhesive layer is a thermal transfer medium containing two layers of the provided adhesive layers, which are a cyclized rubber and a chlorinated polyolefin.
Further, the present invention includes a transfer layer provided on a base material so as to be thermally transferable, and the transfer layer includes two layers, a colored layer and a protective layer provided on the base material side of the colored layer, and the protection is provided. The layer is a thermal transfer medium containing a cyclized rubber and the colored layer containing an epoxy resin.
The cyclized rubber is insoluble in alcohol, has excellent heat-sensitive adhesiveness to the surface of various plastics such as polyester, and has excellent compatibility with various binder resins forming a transfer layer.

In Patent Document 4, a cyclized rubber is included in the colored layer which is a single transfer layer.
However, in many cases, the colored layer is set to have a large thickness in order to increase the color density of characters and the like, and it is difficult for the film to be sharpened.
In addition, since the cyclized rubber itself is also a component that makes it difficult for the film to be sharpened, in the examples of Patent Document 4, in order to improve the film sharpness of the colored layer and prevent the occurrence of residual peeling, in the same layer, It contains a large amount of wax with low film-forming property.

However, when a large amount of wax is contained, there is a problem that the effect of improving the heat-sensitive adhesiveness, transferability, solvent resistance, and scratch resistance of the cyclized rubber cannot be sufficiently obtained.
On the other hand, in the present invention, the cyclized rubber having the above function is included in a layer (adhesive layer) provided on the outermost layer of the transfer layer, which is directly adhered to the surface of the plastic at the time of thermal transfer printing, for example. Regardless of the type of plastic to be subjected to thermal transfer printing, the heat-sensitive adhesiveness and transferability of the transfer layer can be improved, and transfer defects can be less likely to occur during thermal transfer printing.

Further, the adhesive layer can be made smaller in thickness than the colored layer, and good film sharpness can be ensured without blending a large amount of paraffin or the like. Therefore, in combination with the function of the cyclized rubber, characters or the like printed by thermal transfer printing can be obtained. Solvent resistance and scratch resistance can be improved.
Further, when the cyclized rubber is included in a layer (protective layer) located on the surface side of the colored layer and having a function of protecting the layer below the colored layer, for example, characters after thermal transfer printing, the cyclized rubber is included. The thickness of the protective layer can be made smaller than that of the colored layer, and good film sharpness can be ensured without adding a large amount of paraffin, etc., and the solvent resistance of thermal transfer printed characters, etc. Abrasion resistance can be improved.

Further, if the protective layer is combined with a colored layer or the like having excellent heat-sensitive adhesiveness to the surface of the plastic to be subjected to thermal transfer printing, the transfer layer is imparted with good transferability according to the type of plastic and is thermally transferred. It is also possible to prevent transfer defects from occurring during printing.
In Patent Document 5, a colored layer containing cyclized rubber is formed on one side of a polyester film as a base material. However, the colored layer containing the cyclized rubber is a colored layer having the same color as the heat-transferred colored layer and which is firmly adhered to the polyester film and is not heat-transferred. It is only formulated to prevent.

The colored layer to be transferred does not contain cyclized rubber, and therefore cannot have the same effect as the present invention.
FIG. 1A is an enlarged cross-sectional view showing a layer structure of an example of an embodiment of the thermal transfer medium of the present invention.
With reference to FIG. 1A, in the thermal transfer medium 1 of this example, the transfer layer 4 is provided on the upper surface (surface) of the base material 2 via the release layer 3, and the base material is described above. In the figure 2, the back surface layer 5 is formed on the lower surface (back surface).

The transfer layer 4 is composed of two layers, a colored layer 6 in contact with the release layer 3 and an adhesive layer 7 provided on the colored layer 6, and the adhesive layer 7 contains cyclized rubber and chlorinated polyolefin. ing.
Therefore, according to the thermal transfer medium 1 of this example, the function of the cyclized rubber described above improves the thermal adhesiveness and transferability of the transfer layer 4 regardless of the type of plastic as the target of thermal transfer printing, and thermal transfer is performed. Transfer defects can be less likely to occur during printing. In addition, solvent resistance and scratch resistance of characters printed by thermal transfer printing can be improved.

<< Base material 2 >>
Examples of the base material 2 include resin films such as polyester, polysulfone, polystyrene, polyamide, polyimide, polycarbonate, PP, PE, and triacetate; thin leaf paper such as condenser paper and glassin paper; and cellophane and the like.
Among them, polyester films such as PET and polyethylene naphthalate are preferable from the viewpoints of mechanical strength, dimensional stability, heat resistance, price and the like.

The thickness of the base material 2 is preferably 1 μm or more, particularly preferably 2 μm or more, and preferably 30 μm or less, particularly 15 μm or less.
By setting the thickness to this range or more, it is possible to secure an appropriate tensile strength or the like on the base material 2.
Further, by setting the thickness to the above range or less, the heat applied from the back surface side of the base material 2 by the thermal head of the thermal transfer printer is transferred to the peeling layer 3 and the transfer layer 4 as efficiently as possible through the base material 2. The thermal sensitivity of the thermal transfer medium 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to poor transfer.

<< Peeling layer 3 >>
As the release layer 3, the transfer layer 4 is continuously fixed to the surface of the base material 2 until the heat-sensitive transfer medium 1 is used for thermal transfer printing, and the heat-sensitive transfer medium 1 is used from the back surface side of the base material 2 by the thermal head. Examples thereof include layers made of various materials having a function of melting or softening by heating to peel the transfer layer 4 from the base material 2.

Examples of the material for forming the release layer 3 include waxes such as polyethylene wax, carnauba wax, paraffin wax, microcrystallin wax, and Fishertropsh wax, or polyethylene-based copolymers, poly (meth) acrylic acid esters, and vinyl chloride-based materials. (Co) Examples thereof include one or more types such as a copolymer and a thermoplastic resin such as a polyester resin.

Wax is particularly preferable.
Further, a thermoplastic resin such as ethylene vinyl acetate resin (EVA) may be added to the wax in order to prevent so-called spillage, in which the transfer layer 4 before thermal transfer is peeled off from the base material 2.
The peeling layer 3 preferably has a melting point or softening point of 50 ° C. or higher, particularly 60 ° C. or higher, and preferably 150 ° C. or lower, particularly 120 ° C. or lower, in consideration of satisfactorily exhibiting the above-mentioned functions. ..

In order to form the release layer 3 having a melting point or softening point in the above range, one of the above-exemplified waxes and thermoplastic resins having a melting point or softening point in the above range may be selected and used. Two or more kinds of wax and thermoplastic resin may be used in combination and adjusted so that the melting point or the softening point falls within the above range.
The release layer 3 may contain other components in addition to the wax and the thermoplastic resin. Examples of other components include one or more of organic or inorganic fillers, thermosetting resins, higher fatty acids, higher alcohols, higher fatty acid esters, amides, higher amines, oils, surfactants and the like. Be done.

Of these, the surfactant is for adjusting the peelability of the release layer 3, and examples of the surfactant include polyoxyethylene chain-containing compounds and the like.
The release layer 3 is formed by applying a coating agent in which wax or the like, which is the basis thereof, is dissolved or dispersed in a solvent to the surface of the base material 2 and then drying it, or by so-called hot melt coating, the above solid content. Can be formed by applying to the surface of the base material 2 in a state of being heated and melted, and then cooling and solidifying.

^{The thickness of the release layer 3 is preferably 0.1 g / m 2} or more, particularly 0.2 g / m ² or more, and 1.4 g / m ² or less, particularly 1.2 g, in terms of the amount of solid content per unit area. It is preferably / m ² or less.
By setting the thickness to this range or more, a continuous layer that functions well as the release layer 3 can be formed on the surface of the base material 2 to improve the transferability of the transfer layer 4, and the transferability of the transfer layer 4 can be improved. It is possible to satisfactorily suppress the decrease in sharpness.

Further, by setting the thickness of the release layer 3 to the above range or less, the heat applied from the back surface side of the base material 2 by the thermal head is transferred to the transfer layer 4 through the release layer 3 as efficiently as possible, and the heat-sensitive transfer medium. The thermal sensitivity of 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring and deterioration of sharpness of characters and the like due to poor transfer.
<< Transfer layer 4 >>
<Colored layer 6>
Of the transfer layers 4, the colored layer 6 preferably contains a binder resin, wax, and a colorant.

(Binder resin)
Examples of the binder resin include polyester resin, epoxy resin, styrene resin and the like. In particular, it is preferable to use a polyester resin and an epoxy resin together.
Polyester resin has excellent alcohol resistance, and epoxy resin has excellent scratch resistance and gasoline resistance. Therefore, by using both resins in combination, the colored layer 6 located on the surface of characters and the like can function as a protective layer after thermal transfer printing, and the scratch resistance and solvent resistance of the characters and the like can be further improved.

In addition, the epoxy resin improves the film sharpness of the colored layer 6 and eventually the transfer layer 4, and contributes to the prevention of residual peeling and the improvement of the sharpness of characters and the like.
As the polyester resin, various polyester resins which are copolymers or copolymers containing repeating units by ester bonding and which are thermoplastic and solvent-soluble can be used.

Specific examples of the polyester resin include, but are not limited to, one or more of the following polyester resins.
^{Brand 200 [glass transition temperature Tg: 67 ° C., number average molecular weight Mn: 17 × 10 3} ], 220 of the amorphous polyester resins (organic solvent-soluble type) of the Byron (registered trademark) series manufactured by Toyo Boseki Co., Ltd. [Glass transition temperature Tg: 53 ° C., number average molecular weight Mn: 3 × 10 ³ ], 240 [Glass transition temperature Tg: 60 ° C., number average molecular weight Mn: 15 × 10 ³ ], 280 [Glass transition temperature Tg: 68 ° C. , Number average molecular weight Mn: 18 × 10 ³ ], GK640 [Glass transition temperature Tg: 79 ° C., Number average molecular weight Mn: 18 × 10 ³ ], GK880 [Glass transition temperature Tg: 84 ° C., Number average molecular weight Mn: 18 × 10 ³ ].

UE3200 [Glass transition temperature Tg: 65 ° C, softening point: 165 ° C, molecular weight: 16000], UE3201 [Glass transition temperature Tg:] among the thermoplastic saturated copolymerized polyester resins of the Elitel (registered trademark) series manufactured by Unitica Co., Ltd. 65 ° C, softening point: 165 ° C, molecular weight: 20000], UE3203 [glass transition temperature Tg: 60 ° C, softening point: 160 ° C, molecular weight: 20000], UE3230 [glass transition temperature Tg: 3 ° C, softening point: 115 ° C. , UE3210 [Glass transition temperature Tg: 45 ° C, softening point: 155 ° C, molecular weight: 20000], UE3320 [Glass transition temperature Tg: 40 ° C, molecular weight: 18000].

Among the high molecular weight saturated copolymerized polyester resins of the Diacron (registered trademark) series manufactured by Mitsubishi Rayon Co., Ltd., ER-1002 [Glass transition temperature Tg: 60 ° C, melting start temperature: 120 ° C, number average molecular weight Mn: 13500 ], ER-1003 [Glass transition temperature Tg: 50 ° C., melting start temperature: 125 ° C., number average molecular weight Mn: 19000], ER-1004 [Glass transition temperature Tg: 58 ° C., melting start temperature: 124 ° C., number average Molecular weight Mn: 14000], ER-2001 [Glass transition temperature Tg: 15 ° C., melting start temperature: 83 ° C., number average molecular weight Mn: 20000].

Examples of the epoxy resin include bisphenol A type epoxy resin; bisphenol F type epoxy resin; phenol novolac type epoxy resin; cresol novolac type epoxy resin; alicyclic epoxy resin; hydrogenated bisphenol A type epoxy resin; hydrogenated bisphenol AD type. Epoxy resin; aliphatic epoxy resin such as propylene glycol glycoxyl ether, pentaerythritol polyglycidyl ether; epoxy resin obtained from aliphatic or aromatic amine and epichlorohydrin; obtained from aliphatic or aromatic carboxylic acid and epichlorohydrin Various epoxy resins such as epoxy resin; heterocyclic epoxy resin, spiro ring-containing epoxy resin; epoxy-modified resin; brominated epoxy resin can be used.

Specific examples of the epoxy resin include, but are not limited to, one or more of the following epoxy resins, which are basic solid types manufactured by Mitsubishi Chemical Corporation and which are solid at room temperature. The softening points of the epoxy resin are all based on the ring-and-ball method.
Grade 1001 [softening point: 64 ° C., molecular weight: about 900], 1002 [softening point: 78 ° C., molecular weight: about 1200], 1003 [softening point: 89 ° C., molecular weight: about 1300], 1055 [softening point: 93 ° C.] , Molecular weight: about 1600], 1004 [softening point: 97 ° C., molecular weight: about 1650], 1004AF [softening point: 97 ° C., molecular weight: about 1650], 1007 [softening point: 128 ° C., molecular weight: about 2900], 1009 [Softening point: 144 ° C., molecular weight: about 3800], 1010 [molecular weight: about 5500], 1003F [softening point: 96 ° C.], 1004F [softening point: 103 ° C.], 1005F, 1009F [softening point: 144 ° C.], 1004FS [softening point: 100 ° C.], 1006FS [softening point: 112 ° C.], 1007FS [softening point: 124 ° C.].

(Mixing ratio and mixing ratio)
The blending ratio of the polyester resin P and the epoxy resin E is preferably 0.5 or more, particularly preferably 1 or more, and particularly preferably 7 or less, particularly 5 or less, in terms of the mass ratio P / E of both.
If the amount of polyester resin is less than this range, the alcohol resistance of characters and the like may decrease.

On the other hand, if the amount of epoxy resin is less than the above range, the scratch resistance and gasoline resistance of characters and the like may decrease. Further, the colored layer 6 and the transfer layer 4 may not be easily sharpened, resulting in residual peeling and deterioration of the sharpness of characters and the like.
On the other hand, by setting the blending ratio of the polyester resin and the epoxy resin within the above range, the functions of both resins are well balanced, and as described above, the colored layer 6 located on the surface of characters or the like after thermal transfer printing. Can function as a protective layer to further improve the scratch resistance and solvent resistance of the characters and the like. Further, the film sharpness of the colored layer 6 and the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of characters and the like.

The total blending ratio of both resins is the remaining amount of other components constituting the colored layer 6. That is, the blending ratios of the wax, the colorant, etc. are set within the predetermined ranges, and the blending ratios of the two resins are set so that the total amount of the solid content obtained by adding the polyester resin and the epoxy resin as the binder resin is 100 parts by mass. You can set it.
(wax)
As the wax, various natural or synthetic waxes can be used. Examples of the wax include one or more types such as polyethylene wax, carnauba wax, paraffin wax, microcrystalline wax, and Fishertropch wax.

The melting point of the wax is preferably 90 ° C. or higher, and preferably 115 ° C. or lower.
The mixing ratio of the wax is preferably 3 parts by mass or more, particularly 5 parts by mass or more, and particularly 15 parts by mass or less, particularly 12 parts by mass or less, based on 100 parts by mass of the total solid content forming the colored layer 6. Is preferable.
Wax is a component that has a lower film-forming property than the binder resin, so that it improves the film sharpness of the colored layer 6 and eventually the transfer layer 4 and contributes to the prevention of residual peeling and the improvement of sharpness. If it is less than the range, such an effect may not be sufficiently obtained.

On the other hand, when the mixing ratio of the wax exceeds the above range, the ratio of the binder resin responsible for film formation is relatively insufficient, so that the solvent resistance of characters and the like is lowered or the abrasion resistance is lowered. , There is a risk that characters and the like may be blurred or the sharpness may be reduced due to friction.
On the other hand, by setting the mixing ratio of the wax in the above range, the film sharpness of the colored layer 6 and the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of the characters and the like. It is possible to improve the solvent resistance and scratch resistance of the product, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.

(Colorant)
As the colorant, one or two or more kinds of colorants such as pigments can be used depending on the color of the color layer 6. In particular, a pigment is preferable as the colorant in consideration of improving the weather resistance of characters and the like.
The blending ratio of the pigment is preferably 20 parts by mass or more, particularly 25 parts by mass or more, and particularly 70 parts by mass or less, particularly 65 parts by mass or less, based on 100 parts by mass of the total solid content forming the colored layer 6. Is preferable.

If the blending ratio of the pigment is less than this range, the color density of characters and the like may be insufficient.
Further, since the pigment does not have film-forming properties, it is a component that improves the film sharpness of the colored layer 6 and eventually the transfer layer 4 and contributes to prevention of residual peeling and improvement of sharpness. However, such an effect may not be sufficiently obtained.
On the other hand, when the blending ratio of the pigment exceeds the above range, the ratio of the binder resin responsible for film formation is relatively insufficient, so that the solvent resistance of characters and the like is lowered or the abrasion resistance is lowered. , There is a risk that characters and the like may be blurred or the sharpness may be reduced due to friction.

On the other hand, by setting the blending ratio of the pigment in the above range, the film sharpness of the colored layer 6 and the transfer layer 4 can be improved to prevent residual peeling, and the color density and sharpness of characters and the like can be improved. It is possible to improve the solvent resistance and scratch resistance of the characters and the like, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.
The blending ratio of the pigment can be appropriately changed within the above range according to the color, type, hiding power and the like. For example, the blending ratio required to obtain the same level of hiding power as when carbon black (black) is blended at a ratio of about 50 parts by mass is about 70 parts by mass for titanium oxide (white) and 50 parts for phthalocyanine (blue). About parts by mass, magenta (red) is about 55 parts by mass.

When a pigment is used as the colorant, a dispersant or the like may be added in order to improve its dispersibility.
(Colored layer 6)
The colored layer 6 can be formed by applying a coating agent in which each of the above components is dissolved or dispersed in a solvent onto the release layer 3 and then drying it. When the colorant is a pigment, the coating agent can be prepared, for example, by dissolving a binder resin and wax in a solvent, and then adding the pigment and pulverizing and dispersing.

^{The thickness of the colored layer 6 is preferably 0.5 g / m 2} or more, particularly 0.6 g / m ² or more, and 1.5 g / m ² or less, particularly 1.3 g, in terms of the solid content per unit area. It is preferably / m ² or less.
By setting the thickness of the coloring layer 6 to this range or more, the color density of characters and the like can be sufficiently improved.
On the other hand, by setting the thickness of the colored layer 6 to the above range or less, the film sharpness of the colored layer 6 and eventually the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of characters and the like. Further, the thermal sensitivity of the thermal transfer medium 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to transfer failure.

<Adhesive layer 7>
Adhesive layer 7 to form a transfer layer 4 with the colored layers 6, cyclized rubber as described above, and with the chlorinated polyolefin, that contains a word box, and microparticles preferred.
When a cyclized rubber having excellent heat-sensitive adhesiveness to the surface of polyester is used in combination with a chlorinated polyolefin having good heat-sensitive adhesiveness to the surface of polyolefin, the range of plastics that can be thermally transferred and printed is expanded, and the heat-sensitive transfer medium 1 is used for general purposes. Can improve sex.

Further, when wax is used in combination, the melt viscosity of the adhesive layer 7 at the time of thermal transfer printing can be lowered, the adhesion to the surface of the plastic can be improved, and the thermal adhesiveness and transferability of the transfer layer 4 can be further improved. Therefore, it is possible to more satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to poor transfer.
Furthermore, when a wax having low film-forming property and fine particles having no film-forming property are used in combination, the film sharpness of the adhesive layer 7 and the transfer layer 4 is improved to prevent residual peeling and improve the sharpness of characters and the like. You can do it.

(Rubber cyclization)
As the cyclized rubber, various cyclized rubbers synthesized by treating natural rubber or various synthetic rubbers with an acid can be used.
Specific examples of the cyclized rubber are not limited to this, but for example, among the cyclized rubbers of the Alpex (registered trademark) series manufactured by Ornex, CK450 [glass transition temperature Tg: about 90 ° C., softening point: 122 to 138 ° C. , Number average molecular weight Mn: about 5000], CK514 [Glass transition temperature Tg: about 90 ° C., softening point: 110-126 ° C., number average molecular weight Mn: about 2500] and the like.

(Chlorinated polyolefin)
As the chlorinated polyolefin, various chlorinated polyolefins having a structure in which chlorine is introduced into the molecules of polyolefins such as PP and PE can be used.
Specific examples of the chlorinated polyolefin include, but are not limited to, one or more of the following chlorinated polyolefins in the Supercron (registered trademark) series manufactured by Nippon Paper Industries, Ltd.

Brand C [Chlorine content: 35%, Solid content: 55%], L-206 [Chlorine content: 32%, Solid content: 50%], 813A [Chlorine content: 30%, Solid content: 55%] , 803M [Chlorine content: 30%, Solid content: 30%], 803MW [Chlorine content: 29.5%, Solid content: 20%], 803LT [Chlorine content: 29.5%, Solid content: 30] %], 1026 [Chlorine content: 26%, Solid content: 30%], 803L [Chlorine content: 26%, Solid content: 30%], 814HS [Chlorine content: 41%], 390S [Chlorine content] : 36%].

(Mixing ratio and mixing ratio)
The blending ratio of the cyclized rubber C and the chlorinated polyolefin O is preferably 0.5 or more, particularly preferably 1 or more, and preferably 6 or less, particularly 5 or less in terms of mass ratio C / O.
If the amount of cyclized rubber is less than this range, the heat-sensitive adhesiveness to the surface of polyester or the like and the transferability associated therewith become insufficient, causing transfer defects during thermal transfer printing or solvent resistance of characters or the like printed by thermal transfer printing. , The scratch resistance may decrease.

Further, when the amount of chlorinated polyolefin is less than the above range, the heat-sensitive adhesiveness to the surface of the polyolefin or the like and the transferability associated therewith become insufficient, resulting in transfer failure during thermal transfer printing or thermal transfer printing of characters and the like. Solvent resistance and scratch resistance may decrease.
On the other hand, by setting the compounding ratio of the cyclized rubber and the chlorinated polyolefin in the above range, the functions of both resins are well balanced, and as described above, the range of the plastic that can be subjected to thermal transfer printing is expanded, and the feeling is felt. The versatility of the thermal transfer medium 1 can be improved.

The total blending ratio of both resins is the remaining amount of other components constituting the adhesive layer 7. That is, the blending ratio of wax, fine particles, etc. is set within a predetermined range, and the blending ratio of both resins is set so that the total amount of the solid content including the cyclized rubber and the chlorinated polyolefin is 100 parts by mass. do it.
(wax)
As the wax, various natural or synthetic waxes can be used. Examples of the wax include one or more types such as polyethylene wax, carnauba wax, paraffin wax, microcrystalline wax, and Fishertropch wax.

The melting point of the wax is preferably 90 ° C. or higher, and preferably 115 ° C. or lower.
The mixing ratio of the wax is preferably 3 parts by mass or more, particularly preferably 5 parts by mass or more, and particularly 10 parts by mass or less, particularly 8 parts by mass or less, based on 100 parts by mass of the total solid content forming the adhesive layer 7. Is preferable.
If the mixing ratio of the wax is less than this range, the effect of lowering the melt viscosity of the adhesive layer 7 at the time of thermal transfer printing and improving the heat-sensitive adhesiveness and transferability of the transfer layer 4 cannot be obtained by blending the wax. There is a risk. Further, there is a possibility that the effect of improving the film sharpness of the adhesive layer 7 and eventually the transfer layer 4 to prevent residual peeling and improving the sharpness of characters and the like cannot be obtained.

On the other hand, when the mixing ratio of the wax exceeds the above range, the ratio of the cyclized rubber and the chlorinated polyolefin, which are relatively responsible for film formation, is insufficient, so that the solvent resistance of characters and the like is lowered or the abrasion resistance is reduced. There is a risk that the character will be blurred or the sharpness will be reduced due to friction.
On the other hand, by setting the blending ratio of the wax in the above range, the heat-sensitive adhesiveness and transferability of the transfer layer 4 are improved, the film sharpness is improved, the residual peeling is prevented, and the sharpness of characters and the like is improved. In addition to being able to improve, it is possible to improve the solvent resistance and scratch resistance of the characters and the like, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.

(Fine particles)
As the fine particles, various fine particles of inorganic or organic can be used. Examples of such fine particles include fillers such as calcium carbonate, pigments, and the like. In particular, when a pigment having the same color or a similar color as that contained in the colored layer 6 is contained in the adhesive layer 7 as fine particles, The color density of characters and the like can be further improved. Further, for example, even when the colored layer 6 is worn, it is possible to maintain the color of characters and the like.

The blending ratio of the fine particles such as pigments is preferably 10 parts by mass or more, particularly 20 parts by mass or more, and 50 parts by mass or less, particularly 40 parts by mass, based on 100 parts by mass of the total solid content forming the adhesive layer 7. It is preferably as follows.
If the blending ratio of the fine particles is less than this range, the effect of improving the film sharpness of the adhesive layer 7 and the transfer layer 4 by the fine particles to prevent residual peeling and improving the sharpness of characters and the like can be obtained. It may not be possible.

On the other hand, when the compounding ratio of the fine particles exceeds the above range, the ratio of the cyclized rubber and the chlorinated polyolefin, which are relatively responsible for film formation, is insufficient, so that the solvent resistance of characters and the like is lowered or the resistance is reduced. The scratchability is reduced, and there is a risk that characters and the like may be blurred or the sharpness may be reduced due to friction.
On the other hand, by setting the blending ratio of the fine particles within the above range, it is possible to improve the film sharpness of the adhesive layer 7 and eventually the transfer layer 4 to prevent residual peeling and improve the sharpness of the characters and the like. It is possible to improve solvent resistance and scratch resistance such as, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.

The blending ratio of the fine particles is, for example, the total amount of two or more kinds of fine particles used in combination with the pigment and other fine particles as the fine particles.
(Adhesive layer 7)
The adhesive layer 7 can be formed by applying a coating agent in which each of the above components is dissolved or dispersed in a solvent onto the colored layer 6 and then drying it. Further, the coating agent can be prepared, for example, by dissolving cyclized rubber, chlorinated polyolefin, and wax in a solvent, and then adding fine particles to pulverize and disperse.

^{The thickness of the adhesive layer 7 is preferably 0.1 g / m 2} or more, particularly 0.2 g / m ² or more, and 0.8 g / m ² or less, particularly 0.7 g, in terms of the solid content per unit area. It is preferably / m ² or less.
By setting the thickness of the adhesive layer 7 to this range or more, the heat-sensitive adhesiveness and transferability of the transfer layer 4 can be improved, transfer defects can be less likely to occur during thermal transfer printing, and solvent resistance of characters and the like printed by thermal transfer printing can be improved. The scratch resistance can be improved.

On the other hand, by setting the thickness of the adhesive layer 7 to the above range or less, the film sharpness of the adhesive layer 7 and eventually the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of characters and the like. Further, the thermal sensitivity of the thermal transfer medium 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to transfer failure.
<< Back layer 5 >>
The back surface layer 5 is a layer for improving the heat resistance, slipperiness, scratch resistance, etc. of the back surface of the base material 2 that comes into contact with the thermal head.

The back surface layer 5 can be formed in the same manner as before.
That is, the back layer 5 can be formed of a silicone resin, a fluorine resin, a silicone / fluorine copolymer resin, a nitrocellulose resin, a silicone-modified urethane resin, a silicone-modified acrylic resin, or the like. Further, the back layer 5 may contain a lubricant if necessary.
The back layer 5 can be formed by applying a coating agent in which the above resin or the like is dissolved or dispersed in a solvent to the back surface of the base material 2 and then drying it.

The thickness of the back layer 5, 0.05 g / ^{m 2} or more as expressed in terms of solid content per unit area is preferably in particular 0.1 g / ^{m 2} or more, 0.5 g / ^{m 2} or less, particularly 0.4g It is preferably / m ² or less.
By setting the thickness to this range or more, the above-mentioned effect by providing the back surface layer 5 can be sufficiently ensured. On the other hand, by setting the thickness of the back layer 5 to be less than or equal to the above range, the efficiency of heat transfer from the thermal head can be improved and the thermal sensitivity of the heat-sensitive transfer medium 1 can be improved. It is possible to satisfactorily suppress the decrease in the amount of water.

FIG. 1B is an enlarged cross-sectional view showing the layer structure of another example of the embodiment of the thermal transfer medium of the present invention.
With reference to FIG. 1 (b), in the thermal transfer medium 1 of this example, the transfer layer 4 is provided on the upper surface (surface) of the base material 2 via the release layer 3, and the base material is described above. In the figure 2, the back surface layer 5 is formed on the lower surface (back surface).

The transfer layer 4 is composed of two layers, a protective layer 8 in contact with the release layer 3 and a colored layer 9 provided on the protective layer 8, and the protective layer 8 contains a cyclized rubber and the colored layer 9 is formed. Contains epoxy resin.
As described above, the epoxy resin is excellent in scratch resistance and gasoline resistance, and also has heat-sensitive adhesiveness to the surface of various plastics.

Therefore, according to the thermal transfer medium 1 of this example, the functions of both resins improve the thermal adhesiveness and transferability of the transfer layer 4 regardless of the type of plastic as the target of thermal transfer printing, and during thermal transfer printing. It is possible to prevent transfer defects from occurring. In addition, solvent resistance of characters printed by thermal transfer printing, particularly gasoline resistance and scratch resistance can be improved.
In this example, the base material 2, the release layer 3, and the back surface layer 5 can be configured in the same manner as in the previous example, and thus the description thereof will be omitted.

<< Transfer layer 4 >>
<Protective layer 8>
The protective layer 8 preferably contains fine particles together with the above-mentioned cyclized rubber.
When fine particles having no film-forming property are used in combination with the cyclized rubber, the film sharpness of the protective layer 8 and the transfer layer 4 can be improved to prevent residual peeling, and the sharpness of characters and the like can be improved.

Specific examples of the cyclized rubber and the fine particles are the same as in the case of the adhesive layer 7 described above.
The blending ratio of the fine particles is preferably 20 parts by mass or more, particularly 30 parts by mass or more, and particularly 60 parts by mass or less, particularly 50 parts by mass or less, based on 100 parts by mass of the total solid content forming the protective layer 8. Is preferable.
If the blending ratio of the fine particles is less than this range, the effect of improving the film sharpness of the protective layer 8 and the transfer layer 4 by the fine particles to prevent residual peeling and improving the sharpness of characters and the like can be obtained. It may not be possible.

On the other hand, when the blending ratio of the fine particles exceeds the above range, the ratio of the cyclized rubber responsible for film formation is relatively insufficient, so that the solvent resistance of characters and the like is lowered or the abrasion resistance is lowered. As a result, there is a risk that characters and the like will be blurred or the sharpness will be reduced due to friction.
On the other hand, by setting the blending ratio of the fine particles within the above range, it is possible to improve the film sharpness of the protective layer 8 and eventually the transfer layer 4 to prevent residual peeling and improve the sharpness of the characters and the like. It is possible to improve solvent resistance and scratch resistance such as, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.

The blending ratio of the fine particles is, for example, the total amount of two or more kinds of fine particles used in combination with the pigment and other fine particles as the fine particles.
The blending ratio of the cyclized rubber is the remaining amount of other components constituting the protective layer 8. That is, the blending ratio of the fine particles and the like may be set within a predetermined range, and the blending ratio of the cyclized rubber may be set so that the total amount of the solid content to which the cyclized rubber is added is 100 parts by mass.

The protective layer 8 can be formed by applying a coating agent in which each of the above components is dissolved or dispersed in a solvent onto the release layer 3 and then drying the protective layer 8. Further, the coating agent can be prepared, for example, by dissolving the cyclized rubber in a solvent, then adding fine particles and pulverizing and dispersing.
^{The thickness of the protective layer 8 is preferably 0.1 g / m 2} or more, particularly 0.2 g / m ² or more, and 0.8 g / m ² or less, particularly 0.7 g, in terms of the solid content per unit area. It is preferably / m ² or less.

By setting the thickness of the protective layer 8 to this range or more, the solvent resistance and scratch resistance of thermal transfer printed characters and the like can be improved.
On the other hand, by setting the thickness of the protective layer 8 to the above range or less, the film sharpness of the protective layer 8 and eventually the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of characters and the like. Further, the thermal sensitivity of the thermal transfer medium 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to transfer failure.

<Colored layer 9>
The colored layer 9 preferably contains a colorant together with the above-mentioned epoxy resin.
Specific examples of the epoxy resin and the colorant are the same as in the case of the color layer 6 described above.
In particular, as the colorant, a pigment is still preferable in consideration of improving the weather resistance of characters and the like and improving the film sharpness of the colored layer 9.

The blending ratio of the pigment is preferably 20 parts by mass or more, particularly 25 parts by mass or more, and particularly 70 parts by mass or less, particularly 65 parts by mass or less, based on 100 parts by mass of the total solid content forming the colored layer 9. Is preferable.
If the blending ratio of the pigment is less than this range, the color density of characters and the like may be insufficient. Further, there is a possibility that the effect of improving the film sharpness of the colored layer 9 and eventually the transfer layer 4 to prevent residual peeling and improve the sharpness cannot be sufficiently obtained.

On the other hand, when the blending ratio of the pigment exceeds the above range, the ratio of the epoxy resin responsible for film formation is relatively insufficient, so that the solvent resistance of characters and the like, especially the gasoline resistance, is lowered or the abrasion resistance is reduced. There is a risk that the character will be blurred or the sharpness will be reduced due to friction.
On the other hand, by setting the blending ratio of the pigment in the above range, the film sharpness of the colored layer 9 and the transfer layer 4 can be improved to prevent residual peeling, and the color density and sharpness of characters and the like can be improved. It is possible to improve the solvent resistance of the characters and the like, particularly the gasoline resistance and the scratch resistance, and to satisfactorily suppress the occurrence of blurring and deterioration of sharpness.

As in the case of the colored layer 6, the blending ratio of the pigment may be appropriately changed within the above range according to the color, type, hiding power, and the like.
The blending ratio of the epoxy resin is the remaining amount of other components constituting the colored layer 9. That is, the blending ratio of the pigment may be set within a predetermined range, and the blending ratio of the epoxy resin may be set so that the total amount of the solid content to which the epoxy resin is added is 100 parts by mass.

The colored layer 9 can be formed by applying a coating agent in which each of the above components is dissolved or dispersed in a solvent onto the protective layer 8 and then drying it. The coating agent can be prepared, for example, by dissolving an epoxy resin in a solvent, then adding a pigment and pulverizing and dispersing it.
^{The thickness of the colored layer 9 is preferably 0.5 g / m 2} or more, particularly 0.6 g / m ² or more, and 1.5 g / m ² or less, particularly 1.3 g, in terms of the solid content per unit area. It is preferably / m ² or less.

By setting the thickness of the colored layer 9 to this range or more, the color density of characters and the like can be sufficiently improved.
On the other hand, by setting the thickness of the colored layer 9 to the above range or less, the film sharpness of the colored layer 9 and the transfer layer 4 can be improved to prevent residual peeling and improve the sharpness of characters and the like. Further, the thermal sensitivity of the thermal transfer medium 1 can be improved, and it is possible to satisfactorily suppress the occurrence of blurring of characters and the like and deterioration of sharpness due to transfer failure.

The configuration of the thermal transfer medium of the present invention is not limited to that of the examples of FIGS. 1 (a) and 1 (b) described above.
For example, the transfer layer 4 may be formed in a multilayer structure of three or more layers. Even in that case, by including the cyclized rubber in the adhesive layer and / or the protective layer, the thermal adhesiveness and transferability of the transfer layer can be improved regardless of the type of plastic to be subjected to thermal transfer printing, and during thermal transfer printing. In addition to making it difficult for transfer defects to occur, it is possible to improve the solvent resistance and scratch resistance of thermal transfer printed characters and the like.

Further, one side of the base material 2 may be subjected to a mold release treatment to omit the release layer 3.
In addition, various modifications can be made without changing the gist of the present invention.

Hereinafter, the present invention will be further described based on Examples and Comparative Examples, but the configuration of the present invention is not limited to such Examples and Comparative Examples.
<Example 1>
(Base material 2 and back layer 5)
As the base material 2, a PET film having a thickness of 5 μm was used. On the back surface of the base material 2, a back surface layer 5 made of a silicone-based resin and having a solid content of 0.1 g / m ^{2 per unit area was formed.}

(Release layer 3)
50 parts by mass of carnauba wax and 50 parts by mass of paraffin wax (melting point: 65 ° C.) were dissolved in a mixed solvent having a mass ratio of toluene and methyl ethyl ketone at a mass ratio of 1/2 to prepare a coating having a solid content concentration of 20% by mass.
Next, this coating agent was applied to the surface of the base material 2 and then dried to form a release layer 3 having ^{a solid content of 1.0 g / m 2 per unit area.}

(Colored layer 6)
40 parts by mass of polyester resin [Byron 200 manufactured by Toyobo Co., Ltd.], 20 parts by mass of epoxy resin [Grade 1007 manufactured by Mitsubishi Chemical Co., Ltd.], and microcrystallin wax (melting point: 100 ° C.) 10 A mass portion was dissolved in methyl ethyl ketone, and then 30 parts by mass of carbon black [MA8 manufactured by Mitsubishi Chemical Corporation] was added and dispersed by pulverization to prepare a coating having a solid content concentration of 25% by mass.

Next, this coating agent was applied onto the release layer 3 and then dried to form a colored layer 6 having ^{a solid content of 0.8 g / m 2 per unit area.}
The mass ratio P / E of the polyester resin P and the epoxy resin E in the colored layer 6 was 2.0.
(Adhesive layer 7)
40 parts by mass of cyclized rubber [AlpexCK450 manufactured by Ornex Co., Ltd.], 20 parts by mass of chlorinated polyolefin [chlorine content 36%], and 8 parts by mass of microcrystallin wax (melting point: 100 ° C.) by mass of toluene and methyl ethyl ketone. It was dissolved in a mixed solvent having a ratio of 4/1, and then 32 parts by mass of carbon black [MA8 manufactured by Mitsubishi Chemical Corporation] was added and pulverized and dispersed to prepare a coating having a solid content concentration of 15% by mass.

Next, this coating agent is applied onto the colored layer 6 and then dried to form ^{an adhesive layer 7 having a solid content of 0.5 g / m 2} per unit area, as shown in FIG. 1 (a). In addition, a thermal transfer medium 1 provided with a transfer layer 4 having a two-layer structure of the colored layer 6 and the adhesive layer 7 was produced.
The mass ratio C / O of the cyclized rubber C and the chlorinated polyolefin O in the adhesive layer 7 was 2.0.

<Example 2>
The layer shown in FIG. 1A is the same as in Example 1 except that the amount of cyclized rubber to be blended in the coating agent for the adhesive layer 7 is 30 parts by mass and the amount of chlorinated polyolefin is 30 parts by mass. A heat-sensitive transfer medium 1 having a configuration was produced.
The mass ratio C / O of the cyclized rubber C and the chlorinated polyolefin O in the adhesive layer 7 was 1.0.

<Example 3>
The layer shown in FIG. 1A is the same as in Example 1 except that the amount of cyclized rubber to be blended in the coating agent for the adhesive layer 7 is 50 parts by mass and the amount of chlorinated polyolefin is 10 parts by mass. A heat-sensitive transfer medium 1 having a configuration was produced.
The mass ratio C / O of the cyclized rubber C and the chlorinated polyolefin O in the adhesive layer 7 was 5.0.

<Example 4>
The layer shown in FIG. 1A is the same as in Example 1 except that the amount of cyclized rubber to be blended in the coating agent for the adhesive layer 7 is 20 parts by mass and the amount of chlorinated polyolefin is 40 parts by mass. A heat-sensitive transfer medium 1 having a configuration was produced.
The mass ratio C / O of the cyclized rubber C and the chlorinated polyolefin O in the adhesive layer 7 was 0.5.

<Example 5>
FIG. 1 (a) is the same as in Example 1 except that the amount of cyclized rubber to be blended in the coating agent for the adhesive layer 7 is 51.4 parts by mass and the amount of chlorinated polyolefin is 8.6 parts by mass. ), The thermal transfer medium 1 having the layer structure shown in) was produced.
The mass ratio C / O of the cyclized rubber C and the chlorinated polyolefin O in the adhesive layer 7 was 6.0.

< Example 6>
The layer structure shown in FIG. 1 (a) is the same as in Example 1 except that the amount of the polyester resin to be blended in the coating agent for the colored layer 6 is 30 parts by mass and the amount of the epoxy resin is 30 parts by mass. A thermal transfer medium 1 was produced.

The mass ratio P / E of the polyester resin P and the epoxy resin E in the colored layer 6 was 1.0.
<Example 7 >
The layer structure shown in FIG. 1 (a) is the same as in Example 1 except that the amount of the polyester resin to be blended in the coating agent for the colored layer 6 is 50 parts by mass and the amount of the epoxy resin is 10 parts by mass. A thermal transfer medium 1 was produced.

The mass ratio P / E of the polyester resin P and the epoxy resin E in the colored layer 6 was 5.0.
<Example 8 >
The layer structure shown in FIG. 1 (a) is the same as in Example 1 except that the amount of the polyester resin to be blended in the coating agent for the colored layer 6 is 20 parts by mass and the amount of the epoxy resin is 40 parts by mass. A thermal transfer medium 1 was produced.

The mass ratio P / E of the polyester resin P and the epoxy resin E in the colored layer 6 was 0.5.
<Example 9 >
The layer structure shown in FIG. 1 (a) is the same as in Example 1 except that the amount of the polyester resin to be blended in the coating agent for the colored layer 6 is 52 parts by mass and the amount of the epoxy resin is 8 parts by mass. A thermal transfer medium 1 was produced.

The mass ratio P / E of the polyester resin P and the epoxy resin E in the colored layer 6 was 6.5.
<Comparative example 1>
The layer structure shown in FIG. 1A was the same as in Example 1 except that the amount of chlorinated polyolefin blended in the coating agent for the adhesive layer 7 was 60 parts by mass and the cyclized rubber was not blended. A thermal transfer medium 1 was produced.

Comparative Example 1 corresponds to a reproduction of the adhesive layer of Patent Document 3.
<Comparative example 2>
The same as in Example 1 except that 60 parts by mass of a polyester resin [Byron 200 manufactured by Toyobo Co., Ltd.] described above was added to the coating material for the adhesive layer 7 in place of the cyclized rubber and the chlorinated polyolefin. Then, the thermal transfer medium 1 having the layer structure shown in FIG. 1 (a) was prepared.

Comparative Example 2 corresponds to a reproduction of the adhesive layer of Patent Document 2.
<Comparative example 3>
FIG. 1 is the same as in Comparative Example 2 except that 60 parts by mass of a cyclized rubber [AlpexCK450 manufactured by Ornex Co., Ltd.] described above was blended in the coating agent for the colored layer 6 instead of the polyester resin and the epoxy resin. The thermal transfer medium 1 having the layer structure shown in (a) was prepared.

Comparative Example 3 has the same structure of the adhesive layer of Patent Document 2 as in Comparative Example 2 and the colored layer of Patent Document 4 containing cyclized rubber, and is blended with wax to improve alcohol resistance and scratch resistance. It corresponds to a combination with a colored layer with a reduced proportion.
The thermal transfer medium 1 produced in each of the above Examples and Comparative Examples was used in a thermal transfer barcode printer [105SL Plus manufactured by Zebra Technologies] on the surface of PP and the surface of PET to be printed, respectively. After thermal transfer printing of the barcode under the conditions of printing speed: 6 inches / sec and printing density: 25, the following transferability, alcohol resistance, and scratch resistance were evaluated.

<Transportability>
The state of the thermal transfer-printed barcode was visually observed and read with a barcode reader to evaluate the transferability according to the following criteria.
◯: No blurring or residual peeling was observed on the barcode, and the barcode could be read correctly with a barcode reader.

Δ: Slight blurring or residual peeling was observed on the barcode, but it could be read correctly by the barcode reader.
X: Significant blurring or residual peeling was observed on the barcode, and it could not be read correctly by the barcode reader.
<Alcohol resistance>
A cotton rod impregnated with ethanol is reciprocated 50 times under a load of 90 gf (= 0.8826N) on the bar code printed by thermal transfer, and then the state of the bar code is visually observed and the bar code reader is used. The alcohol resistance was evaluated according to the following criteria.

◯: The barcode did not melt, bleed, blur, or flow, and could be read correctly with a barcode reader.
Δ: Although the barcode was slightly melted and smeared, blurred, or flowed, it could be read correctly by the barcode reader.
X: The barcode was significantly melted and smeared, blurred or flowing, and could not be read correctly by the barcode reader.

<Scratch resistance>
After the steel ball is reciprocated 50 times under a load of 900 gf (= 8.826N) on the bar code printed by thermal transfer, the state of the bar code is visually observed and read using a bar code reader. , The scratch resistance was evaluated according to the following criteria.
◯: The barcode was not blurred or its sharpness was not reduced, and it could be read correctly by the barcode reader.

Δ: Although the barcode was slightly blurred or the clarity was reduced, it could be read correctly by the barcode reader.
X: The barcode was significantly blurred or the clarity was reduced, and the barcode reader could not read it correctly.
The results are shown in Tables 1 to 3.

From the results in Table 3, in Comparative Example 1 in which the adhesive layer 7 did not contain the cyclized rubber and contained only the chlorinated polyolefin, the transferability to the surface of PP and the scratch resistance of the characters printed by thermal transfer printing were good. Although it was (○), it was found that the alcohol resistance of the characters, etc. was poor (×).
Further, in Comparative Example 1 above, it was found that the surface of PET was blurred and the transferability was poor (x), and the alcohol resistance and scratch resistance of characters and the like were also poor (x).

Further, Comparative Example 2 in which the adhesive layer 7 did not contain cyclized rubber or chlorinated polyolefin but contained only polyester resin had good transferability to the surface of PET, alcohol resistance such as letters, and scratch resistance (scratch resistance). Although it was (◯), it was found that the surface of PP was blurred and the transferability was poor (×), and the alcohol resistance and scratch resistance of letters and the like were also poor (×). ..
Further, in Comparative Example 3 in which the adhesive layer of Comparative Example 2 and the colored layer containing the cyclized rubber were combined, as in Comparative Example 2, cassoulet was generated on the surface of PP and the transferability was poor (). Not only is the alcohol resistance and scratch resistance of letters and the like poor (x), but the colored layer is less likely to be sharpened, residual peeling occurs, and the transferability to the PET surface is also poor (x). It turned out to be ×).

On the other hand, from the results of Tables 1 and 2, according to Examples 1 to 9 in which the adhesive layer 7 contains the cyclized rubber and the chlorinated polyolefin , transfer is performed regardless of the type of plastic to be thermal transfer printed. By setting all of the properties, alcohol resistance, and scratch resistance to an intermediate level (Δ) or higher, it is possible to prevent transfer defects from occurring during thermal transfer printing, and it is also possible to improve alcohol resistance and scratch resistance of thermal transfer printed characters and the like. understood.

Also from the results of Examples 1 to 5, considering that further improve the effect of the cyclized rubber to be contained in the adhesive layer 7 and the salt iodinated polyolefin down the weight ratio C / O of 0.5 or more, It was found that it is particularly preferable to set it to 1 or more, and it is preferable to set it to 6 or less, particularly 5 or less.
Further, from the results of Examples 1 and 6 to 9 , considering that the above effects are further improved, it is preferable that the colored layer 6 contains a polyester resin and an epoxy resin as the binder resin. It was found that the mass ratio P / E is preferably 0.5 or more, particularly preferably 1 or more, and preferably 7 or less, particularly 5 or less.

<Example 10 >
(Base material 2 and back layer 5)
As the base material 2, a PET film having a thickness of 5 μm was used. On the back surface of the base material 2, a back surface layer 5 made of a silicone-based resin and having a solid content of 0.1 g / m ^{2 per unit area was formed.}
(Release layer 3)
50 parts by mass of carnauba wax and 50 parts by mass of paraffin wax (melting point: 65 ° C.) were dissolved in a mixed solvent having a mass ratio of toluene and methyl ethyl ketone at a mass ratio of 1/2 to prepare a coating having a solid content concentration of 20% by mass.

Next, this coating agent was applied to the surface of the base material 2 and then dried to form a release layer 3 having ^{a solid content of 1.0 g / m 2 per unit area.}
(Protective layer 8)
60 parts by mass of cyclized rubber [AlpexCK450 manufactured by Ornex Co., Ltd.] was dissolved in a mixed solvent having a mass ratio of toluene and methyl ethyl ketone of 4/1, and then 40 parts by mass of light calcium carbonate was added and pulverized and dispersed to obtain a solid content. A coating having a concentration of 15% by mass was prepared.

Next, this coating agent was applied onto the release layer 3 and then dried to form a protective layer 8 having ^{a solid content of 0.5 g / m 2 per unit area.}
(Colored layer 9)
60 parts by mass of epoxy resin [grade 1007 manufactured by Mitsubishi Chemical Corporation] mentioned above is dissolved in methyl ethyl ketone, and then 40 parts by mass of carbon black [MA8 manufactured by Mitsubishi Chemical Corporation] is added and pulverized and dispersed to solidify. A coating having a component concentration of 25% by mass was prepared.

Next, this coating agent is applied onto the protective layer 8 and then dried to form ^{a colored layer 9 having a solid content of 0.8 g / m 2} per unit area, as shown in FIG. 1 (b). A thermal transfer medium 1 provided with a transfer layer 4 having a two-layer structure of the protective layer 8 and the colored layer 9 was produced.
< Comparative example 4 >
FIG. 1 (FIG. 1) is the same as in Example 10 except that 60 parts by mass of a polyester resin [Byron 200 manufactured by Toyobo Co., Ltd.] described above was blended in the coating agent for the colored layer 9 instead of the epoxy resin. A thermal transfer medium 1 having the layer structure shown in b) was prepared.

<Comparative example 5 >
Implemented except that 45 parts by mass of polyester resin [Byron 200 manufactured by Toyobo Co., Ltd.] and 15 parts by mass of Lanox as wax were added to the coating agent for the protective layer 8 instead of the cyclized rubber. In the same manner as in Example 10 , the thermal transfer medium 1 having the layer structure shown in FIG. 1 (b) was produced.
Comparative Example 4 corresponds to a reproduction of the protective layer of Patent Document 1.

The thermal transfer medium 1 produced in each of the above Examples and Comparative Examples is used in a thermal transfer barcode printer [105SL Plus manufactured by Zebra Technologies] to print on the surface of PP and the surface of PET as printing targets, respectively. After thermal transfer printing of the barcode under the conditions of speed: 6 inches / sec and printing density: 25, the above-mentioned alcohol resistance and the following gasoline resistance were evaluated.

<Gasoline resistance>
A cotton rod soaked with gasoline is reciprocated 50 times under a load of 90 gf (= 0.8826N) on the bar code printed by thermal transfer, and then the state of the bar code is visually observed and the bar code reader is used. The gasoline resistance was evaluated according to the following criteria.

◯: The barcode did not melt, bleed, blur, or flow, and could be read correctly with a barcode reader.
× : The barcode was slightly melted and smeared or smeared or flowed, but it could be read correctly by the barcode reader , or the barcode was significantly melted and smeared or smeared or flowed. I couldn't read it correctly.

The results are shown in Table 4.

From the results in Table 4, it was found that in Comparative Example 5 in which the protective layer 8 did not contain the cyclized rubber but contained the polyester resin and Lanox, both alcohol resistance and gasoline resistance were poor (x). ..
Further, in Comparative Example 4 in which the protective layer 8 contained the cyclized rubber but the colored layer 9 contained the polyester resin without containing the epoxy resin, the alcohol resistance was improved, but the gasoline resistance was improved. Was found to be defective (x).
In contrast, according to Example 10 was contained epoxy resin Rutotomoni colored layer 9 impregnated with cyclized rubber in the protective layer 8, as both good alcohol resistance and gasoline resistance (○), thermal transfer printing It was found that the solvent resistance of the printed characters can be improved.

1 Thermal transfer medium 2 Base material 3 Peeling layer 4 Transfer layer 5 Back layer 6 Colored layer 7 Adhesive layer 8 Protective layer 9 Colored layer

Claims (3)

Comprising a rolling Utsushiso provided to be thermally transferred onto the substrate, the transfer layer, the colored layer and the two layers of adhesive layer provided on the outermost layer of the substrate of the colored layer opposite a and transfer layer The adhesive layer is a thermal transfer medium containing cyclized rubber and chlorinated polyolefin. The thermal transfer medium according to claim 1 , wherein the colored layer contains a polyester resin and an epoxy resin. A transfer layer provided to be thermally transferred onto the substrate, wherein the transfer layer comprises a wear color layer, the two layers of the protective layer provided on the substrate side of the colored layer, the protective layer is cyclized It includes a rubber, the colored layer thermal transfer medium that contains an epoxy resin.

Images